<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">

<script type="text/javascript" src="jquery-1.12.0.min.js"></script>

<style type="text/css">
	button{
		width:100px;
	}
	.bt{
	 height: 190px;
	}
</style>

<title>Demojs</title>
</head>
<body>

<button class="bt" id="test">test</button>
<p>asdfaefrytry</p>
<script type="text/javascript">

$("#test").on("click",function(){
	$.post("testfour",function(data){
		alert(data.st_name);
		});
}); 

 /* $("#test").on("click",function(){
	alert("Hello world!");
})  */

</script>
</body>
</html>